1. Field of the Invention
The present invention relates to a radio network controller and a QoS control method used therefor and, more particularly, to an RNC (Radio Network Controller) architecture appropriate for QoS (Quality of Service) control on an IP (Internet Protocol) based UTRAN (Universal Terrestrial Radio Access Network).
2. Description of the Related Art
FIG. 6 shows a protocol stack of a U (User)-plane when an IP based UTRAN directly connects to an IP network. Shown in FIG. 6 is a protocol stack among a base station (Node B), a radio network controller (RNC) and a router as nodes which form the UTRAN. Here, the U-plane is for transferring user information.
In FIG. 6, the base station (Node B) is connected to a user equipment (UE) through a PHY (physical layer) and to the radio network controller (RNC) through an L1 (Layer 1). Other than the above-described protocols, the base station (Node B) is provided with an FP (Frame Protocol), a UDP (User Datagram Protocol), an IP and an L2 (Layer 2).
The radio network controller (RNC) is connected to the base station (Node B) and the router through the L1 and is provided with, other than the above-described protocols, an IPv6 (Internet Protocol version 6), a PDCP (Packet Data Convergence Protocol), an RLC (Radio Link Control), a MAC (Medium Access Control), the FP, the UDP, the IP and the L2.
The router is connected to the radio network controller (RNC) and a core network (CN) not shown through the L1 and is provided with the IPv6 and the L2 other than the above-described protocols.
In conventional mobile communication networks whose representative is a GPRS (General Packet Radio Service), there exists as a user IP layer on the CN side, an SGSN (Serving GPRS Support Node)/GGSN (Gateway GPRS Support Node), which is capsuled by GTP (GPRS Tunneling Protocol) tunneling (see e.g. Keiji Tachikawa: W-CDMA Mobile Communication System 4-4 Packet Communication System, pp. 274-279, published by Maruzen, Co., Ltd., Jun. 25, 2001) and hidden on an UTRAN.
In the above-described IP based UTRAN, however, through the direct connection to an IP network, a user IP layer will be processed by the RNC to connect to the Node B through an IP transport. The above-described IP based UTRAN, therefore, QoS information added in the IP network needs to be reflected on the IP transport by the RNC.
Under these circumstances, an object of the present invention is to solve the above-described problems to provide a radio network controller which enables QoS control taking segmentation and concatenation on a layer basis into consideration and a QoS control method used therefor.